Last year, in a newspaper article headed "I h8 txt msgs: How texting is wrecking our language", John Humphrys argued that texters are "vandals who are doing to our language what Genghis Khan did to his neighbours 800 years ago. They are destroying it: pillaging our punctuation; savaging our sentences; raping our vocabulary. And they must be stopped."

As a new variety of language, texting has been condemned as "textese", "slanguage", a "digital virus". According to John Sutherland of University College London, writing in this paper in 2002, it is "bleak, bald, sad shorthand. Drab shrinktalk ... Linguistically it's all pig's ear ... it masks dyslexia, poor spelling and mental laziness. Texting is penmanship for illiterates."

Ever since the arrival of printing - thought to be the invention of the devil because it would put false opinions into people's minds - people have been arguing that new technology would have disastrous consequences for language. Scares accompanied the introduction of the telegraph, telephone, and broadcasting. But has there ever been a linguistic phenomenon that has aroused such curiosity, suspicion, fear, confusion, antagonism, fascination, excitement and enthusiasm all at once as texting? And in such a short space of time. Less than a decade ago, hardly anyone had heard of it.

The idea of a point-to-point short message service (or SMS) began to be discussed as part of the development of the Global System for Mobile Communications network in the mid-1980s, but it wasn't until the early 90s that phone companies started to develop its commercial possibilities. Text communicated by pagers were replaced by text messages, at first only 20 characters in length. It took five years or more before numbers of users started to build up. The average number of texts per GSM customer in 1995 was 0.4 per month; by the end of 2000 it was still only 35.

The slow start, it seems, was because the companies had trouble working out reliable ways of charging for the new service. But once procedures were in place, texting rocketed. In the UK, in 2001, 12.2bn text messages were sent. This had doubled by 2004, and was forecast to be 45bn in 2007. On Christmas Day alone in 2006, over 205m texts went out. World figures went from 17bn in 2000 to 250bn in 2001. They passed a trillion in 2005. Text messaging generated around $70bn in 2005. That's more than three times as much as all Hollywood box office returns that year.

People think that the written language seen on mobile phone screens is new and alien, but all the popular beliefs about texting are wrong. Its graphic distinctiveness is not a new phenomenon, nor is its use restricted to the young. There is increasing evidence that it helps rather than hinders literacy. And only a very tiny part of it uses a distinctive orthography. A trillion text messages might seem a lot, but when we set these alongside the multi-trillion instances of standard orthography in everyday life, they appear as no more than a few ripples on the surface of the sea of language. Texting has added a new dimension to language use, but its long-term impact is negligible. It is not a disaster.

Although many texters enjoy breaking linguistic rules, they also know they need to be understood. There is no point in paying to send a message if it breaks so many rules that it ceases to be intelligible. When messages are longer, containing more information, the amount of standard orthography increases. Many texters alter just the grammatical words (such as "you" and "be"). As older and more conservative language users have begun to text, an even more standardised style has appeared. Some texters refuse to depart at all from traditional orthography. And conventional spelling and punctuation is the norm when institutions send out information messages, as in this university text to students: "Weather Alert! No classes today due to snow storm", or in the texts which radio listeners are invited to send in to programmes. These institutional messages now form the majority of texts in cyberspace - and several organisations forbid the use of abbreviations, knowing that many readers will not understand them. Bad textiquette.

Research has made it clear that the early media hysteria about the novelty (and thus the dangers) of text messaging was misplaced. In one American study, less than 20% of the text messages looked at showed abbreviated forms of any kind - about three per message. And in a Norwegian study, the proportion was even lower, with just 6% using abbreviations. In my own text collection, the figure is about 10%.

People seem to have swallowed whole the stories that youngsters use nothing else but abbreviations when they text, such as the reports in 2003 that a teenager had written an essay so full of textspeak that her teacher was unable to understand it. An extract was posted online, and quoted incessantly, but as no one was ever able to track down the entire essay, it was probably a hoax.

There are several distinctive features of the way texts are written that combine to give the impression of novelty, but none of them is, in fact, linguistically novel. Many of them were being used in chatroom interactions that predated the arrival of mobile phones. Some can be found in pre-computer informal writing, dating back a hundred years or more.

The most noticeable feature is the use of single letters, numerals, and symbols to represent words or parts of words, as with b "be" and 2 "to". They are called rebuses, and they go back centuries. Adults who condemn a "c u" in a young person's texting have forgotten that they once did the same thing themselves (though not on a mobile phone). In countless Christmas annuals, they solved puzzles like this one:

YY U R YY U B I C U R YY 4 ME

("Too wise you are . . .")

Similarly, the use of initial letters for whole words (n for "no", gf for "girlfriend", cmb "call me back") is not at all new. People have been initialising common phrases for ages. IOU is known from 1618. There is no difference, apart from the medium of communication, between a modern kid's "lol" ("laughing out loud") and an earlier generation's "Swalk" ("sealed with a loving kiss").

In texts we find such forms as msg ("message") and xlnt ("excellent"). Almst any wrd cn be abbrvted in ths wy - though there is no consistency between texters. But this isn't new either. Eric Partridge published his Dictionary of Abbreviations in 1942. It contained dozens of SMS-looking examples, such as agn "again", mth "month", and gd "good" - 50 years before texting was born.

English has had abbreviated words ever since it began to be written down. Words such as exam, vet, fridge, cox and bus are so familiar that they have effectively become new words. When some of these abbreviated forms first came into use, they also attracted criticism. In 1711, for example, Joseph Addison complained about the way words were being "miserably curtailed" - he mentioned pos (itive) and incog (nito). And Jonathan Swift thought that abbreviating words was a "barbarous custom".

What novelty there is in texting lies chiefly in the way it takes further some of the processes used in the past. Some of its juxtapositions create forms which have little precedent, apart from in puzzles. All conceivable types of feature can be juxtaposed - sequences of shortened and full words (hldmecls "hold me close"), logograms and shortened words (2bctnd "to be continued"), logograms and nonstandard spellings (cu2nite) and so on. There are no less than four processes combined in iowan2bwu "I only want to be with you" - full word + an initialism + a shortened word + two logograms + an initialism + a logogram. And some messages contain unusual processes: in iohis4u "I only have eyes for you", we see the addition of a plural ending to a logogram. One characteristic runs through all these examples: the letters, symbols and words are run together, without spaces. This is certainly unusual in the history of special writing systems. But few texts string together long sequences of puzzling graphic units.

There are also individual differences in texting, as in any other linguistic domain. In 2002, Stuart Campbell was found guilty of the murder of his 15-year-old niece after his text message alibi was shown to be a forgery. He had claimed that certain texts sent by the girl showed he was innocent. But a detailed comparison of the vocabulary and other stylistic features of his own text messages and those of his niece showed that he had written the messages himself. The forensic possibilities have been further explored by a team at the University of Leicester. The fact that texting is a relatively unstandardised mode of communication, prone to idiosyncrasy, turns out to be an advantage in such a context, as authorship differences are likely to be more easily detectable than in writing using standard English.

Texters use deviant spellings - and they know they are deviant. But they are by no means the first to use such nonstandard forms as cos "because", wot "what", or gissa "give us a". Several of these are so much part of English literary tradition that they have been given entries in the Oxford English Dictionary. "Cos" is there from 1828 and "wot" from 1829. Many can be found in literary dialect representations, such as by Charles Dickens, Mark Twain, Walter Scott, DH Lawrence, or Alan Bleasdale ("Gissa job!").

Sending a message on a mobile phone is not the most natural of ways to communicate. The keypad isn't linguistically sensible. No one took letter-frequency considerations into account when designing it. For example, key 7 on my mobile contains four symbols, pqrs. It takes four key-presses to access the letter s, and yet s is one of the most frequently occurring letters in English. It is twice as easy to input q, which is one of the least frequently occurring letters. It should be the other way round. So any strategy that reduces the time and awkwardness of inputting graphic symbols is bound to be attractive.

Abbreviations were used as a natural, intuitive response to a technological problem. And they appeared in next to no time. Texters simply transferred (and then embellished) what they had encountered in other settings. We have all left notes in which we have replaced an and by an &, a three by a 3, and so on. Anglo-Saxon scribes used abbreviations of this kind.

But the need to save time and energy is by no means the whole story of texting. When we look at some texts, they are linguistically quite complex. There are an extraordinary number of ways in which people play with language - creating riddles, solving crosswords, playing Scrabble, inventing new words. Professional writers do the same - providing catchy copy for advertising slogans, thinking up puns in newspaper headlines, and writing poems, novels and plays. Children quickly learn that one of the most enjoyable things you can do with language is to play with its sounds, words, grammar - and spelling.

The drive to be playful is there when we text, and it is hugely powerful. Within two or three years of the arrival of texting, it developed a ludic dimension. In short, it's fun.

To celebrate World Poetry day in 2007, T-Mobile tried to find the UK's first "Txt laureate" in a competition for the best romantic poem in SMS. They had 200 entrants, and as with previous competitions the entries were a mixture of unabbreviated and abbreviated texts.

The winner, Ben Ziman-Bright, wrote conventionally:

The wet rustle of rain

can dampen today. Your text

buoys me above oil-rainbow puddles

like a paper boat, so that even

soaked to the skin

I am grinning.

The runner-up did not:

O hart tht sorz

My luv adorz

He mAks me liv

He mAks me giv

Myslf 2 him

As my luv porz

(The author of the latter was, incidentally, in her late 60s.)

The length constraint in text-poetry fosters economy of expression in much the same way as other tightly constrained forms of poetry do, such as the haiku or the Welsh englyn. To say a poem must be written within 160 characters at first seems just as pointless as to say that a poem must be written in three lines of five, seven, and five syllables. But put such a discipline into the hands of a master, and the result can be poetic magic. Of course, SMS poetry has some way to go before it can match the haiku tradition; but then, haikus have had a head-start of several hundred years.

There is something about the genre which has no parallel elsewhere. This is nothing to do with the use of texting abbreviations. It is more to do with the way the short lines have an individual force. Reading a text poem, wrote Peter Sansom, who co-judged a Guardian competition in 2002, is "an urgent business ... with a text poem you stay focused as it were in the now of each arriving line." The impact is evident even in one-liners, whose effect relies on the kind of succinctness we find in a maxim or proverb. UA Fanthorpe, Sansom's fellow judge, admired "Basildon: imagine a carpark." And they both liked "They phone you up, your mum and dad."

Several competitions have focussed on reworking famous lines, titles, or quotations:

txt me ishmael

zen & T @ f m2 cycl mn10nc

The brevity of the SMS genre disallows complex formal patterning - of, say, the kind we might find in a sonnet. It isn't so easy to include more than a couple of images, such as similes, simply because there isn't the space. Writers have nonetheless tried to extend the potential of the medium. The SMS novel, for example, operates on a screen-by-screen basis. Each screen is a "chapter" describing an event in the story. Here is an interactive example from 2005, from an Indian website called "Cloakroom":

In Japan, an author known as Yoshi has had a huge success with his text-messaging novel Deep Love. Readers sent feedback as the story unfolded, and some of their ideas were incorporated into it. He went on to make a film of the novel.

A mobile literature channel began in China in 2004. The "m-novel", as it is called, started with a love story, "Distance", by writer and broadcaster Xuan Huang. A young couple get to know each other because of a wrongly sent SMS message. The whole story is 1008 Chinese characters, told in 15 chapters, with one chapter sent each day.

Plainly, there are severe limits to the expressive power of the medium, when it is restricted to a screen in this way. So it is not surprising that, very early on, writers dispensed with the 160-character constraint, and engaged in SMS creative writing of any length using hard copy. Immediately there was a problem. By taking the writing away from the mobile phone screen, how could the distinctiveness of the genre be maintained? So the stylistic character of SMS writing changed, and texting abbreviations, previously optional, became obligatory.

Several SMS poets, such as Norman Silver, go well beyond text-messaging conventions, introducing variations in line-shape, type-size, font, and colour that are reminiscent of the concrete poetry creations of the 1960s. They illustrate the way the genre is being shaped by the more powerful applications available on computers.

In 2007 Finnish writer Hannu Luntiala published The Last Messages, in which the whole 332-page narrative consists of SMS messages. It tells the story of an IT-executive who resigns his job and travels the world, using text messages to keep in touch with everyone. And the growing independence of the genre from its mobile-phone origins is well illustrated by the French novelist Phil Marso, who published a book in 2004 written entirely in French SMS shorthand, Pas Sage a Taba vo SMS - a piece of word-play intended to discourage young people from smoking. The next year he produced L, an SMS retelling of French poetic classics.

An extraordinary number of doom-laden prophecies have been made about the supposed linguistic evils unleashed by texting. Sadly, its creative potential has been virtually ignored. But five years of research has at last begun to dispel the myths. The most important finding is that texting does not erode children's ability to read and write. On the contrary, literacy improves. The latest studies (from a team at Coventry University) have found strong positive links between the use of text language and the skills underlying success in standard English in pre-teenage children. The more abbreviations in their messages, the higher they scored on tests of reading and vocabulary. The children who were better at spelling and writing used the most textisms. And the younger they received their first phone, the higher their scores.

Children could not be good at texting if they had not already developed considerable literacy awareness. Before you can write and play with abbreviated forms, you need to have a sense of how the sounds of your language relate to the letters. You need to know that there are such things as alternative spellings. If you are aware that your texting behaviour is different, you must have already intuited that there is such a thing as a standard. If you are using such abbreviations as lol and brb ("be right back"), you must have developed a sensitivity to the communicative needs of your textees.

Some people dislike texting. Some are bemused by it. But it is merely the latest manifestation of the human ability to be linguistically creative and to adapt language to suit the demands of diverse settings. There is no disaster pending. We will not see a new generation of adults growing up unable to write proper English. The language as a whole will not decline. In texting what we are seeing, in a small way, is language in evolution.

· Txtng: The Gr8 Db8 is published this week by OUP. To order a copy for £9.99 with free UK p&p go to theguardian.com/bookshop